Cutter-head



2 Sheets-Sheet 1.

W 1). STIROKLBR.

CUTTER. HEAD. 4 No. 296.481. Patented. Apr. 8, 1884.

zl/z ffiesgasi I J 722671279) @2. p @w (No Model.) J. D STIRGKLER. 2Sheets -fiheet. 2.

CUTTER HEAD.

Patented Apr. 8,1884.

Ira/@7625!) UNITED STATES PATENT Fries.

JOH). D. S'IIBCKLER, OF WORCESTER, ASSIGNOR TO OSCAR L. NOBLE, OF

' BOSTON, MASSACHUSETTS.

CUTTER-HEAD.

SPECIFICATION forming part of Letters Patent No. 296,481, dated April 8,1884.

(No model.)

To aZZ whom it may concern:

Be it known that I, J OHN D. STrRcKLER, of Worcester, in the county ofWorcester and State of Massachusetts, have invented certain Improvementsin Rotary Gutters, of which the following is a specification.

My invention consists in a cutter formed from a blank having a number offaces, and having radii of different lengths, but having each faceformed on the are of a circle having greater radius than the longerradius of the blank, so that each face, will drop gradually from itslonger to its shorter radius, and the cut-tingedges will not be loweredrapidly by wear and grinding. v

The invention also consists in the improved method of forming the faceson the blank fromwhich the cutter is made, all of which I will nowproceed to describe and claim.

Of the accompanying drawings, forming a part of this specification,Figure 1 represents a side view of a completed cutter constructed inaccordance with my invention. Fig. 2 represents a diagram, showing therelative outlines of the blank before and after the formation of one ofthe faces thereon. Fig. 3 represents an elevation of the means employedto form the faces on the blank. Fig. 4. represents plete circles, tomore'clearly illustrate my improvement.

The same letters of reference indicate the same parts in all thefigures.

In carrying out my invention I take a circular blank, (a portion of theperiphery of which is indicated by the lines 2 3 in Fig. 2,) and formupon its perimeter a series of faces, a, each of which is the arc of acircle having a greater radius than that of the blank, as clearly shownin Fig. 4. In said figure the circle 4. indicates the original peripheryof the blank, and the circles 5 are continuations of the arcs on whichthe faces a are formed. The blank is thus formed with radii of differentlengths, the longer radii being the distance from. the center of theblank to the angles formed by the intersection of the different faces,and the shorter radii being the distance from the center of the blank topoints midway between said angles. The center of the circle tooth.

on which each face is formed is on a line which is a prolongation of theshorter radius of said face. The blank is then slotted, as shown at s s,Fig. 1, one side of each slot intersecting the perimeter of the blank atone of the longer radii thereof, and forming the cutting-edge of atooth, while the other side intersects the perimeter of the blank at oneof its shorter radii, and forms the back of the preceding It will beseen that the faces of the blank are caused by their described form todrop gradually from the cutting-edges to the backs of the teeth, so thatwhen the front faces of the teeth are worn away by use and grinding thecutting-edges are not rapidly lowered to the radii of the backs of theteeth, but are caused to approach said radii very slowly and gradually,so that the cutting-edges retain their clearance until they are worn soas to almost meet the backs of the teeth. The faces a are perfectlyformed by securing a series of blanks to a rotating face-plate, c, andfixing a lathe-tool, d, in the proper relationto said plate, so that itwill act successively on the blanks as the face-plate rotates. When oneface has been formed in this manner on each blank, the blanks areadjusted so that the next face will be formed in the same way, and soon. This constitutes a simple, inexpensive, and effectual method offorming the faces.

It is obvious that the faces may be formed either before or after theslots 8 are formed.

This cutter is intended, chiefly, for trimming the edges of boot andshoe soles, its faces being molded transversely to the form to beimparted to the sole-cdge.

I claim--- A rotary cutter composed of a slotted body and teeth, havingfaces a a formed as arcs of circles, the radii of such arcs [beinglonger than the radii of the body, as set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 26th day of January, 1884.

JOHN D. STIRCKLER.

